Lateral stability simulation and analysis for wheel loaders based on the steady-state margin angle

Wheel loaders are prone to lateral tilting accidents due to their complex working environment, variable structure frame and the large offset of the centroid position. The accidents may seriously threaten the driver’s safety. This paper proposes a steady-state margin (SSM) angle as a new instability threat indicator to analyse lateral stability of wheel loaders. Firstly, the structural characteristics and the rollover process of a wheel loader are presented, and the SSM angle is defined. Secondly, on the assumption that the tyres are rigid, the calculation process of the SSM angle is described in detail, then the SSM angle of the XG953 wheel loader is computed. A virtual prototyping simulation was performed under the environment of ADAMS. The maximum relative error between the theoretical calculation and simulated result was 4.55%, within the permissible speed range. When changing the tyre parameters to normal tyre parameters, the relative error became larger. Finally, an indirect method is proposed to deal with the influence of tyres on the SSM angle and reduce the relative error.